Messages in this thread | | | Date | Wed, 30 Aug 2023 12:52:24 +0200 | From | Lukasz Majewski <> | Subject | Re: [PATCH 2/2] net: phy: Provide Module 4 KSZ9477 errata (DS80000754C) |
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Hi Oleksij,
> On Wed, Aug 30, 2023 at 11:21:19AM +0200, Lukasz Majewski wrote: > > The KSZ9477 errata points out (in 'Module 4') the link up/down > > problem when EEE (Energy Efficient Ethernet) is enabled in the > > device to which the KSZ9477 tries to auto negotiate. > > > > The suggested workaround is to clear advertisement of EEE for PHYs > > in this chip driver. > > > > Signed-off-by: Lukasz Majewski <lukma@denx.de> > > --- > > drivers/net/phy/micrel.c | 31 ++++++++++++++++++++++++++++++- > > 1 file changed, 30 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c > > index 87b090ad2874..469dcd8a5711 100644 > > --- a/drivers/net/phy/micrel.c > > +++ b/drivers/net/phy/micrel.c > > @@ -1418,6 +1418,35 @@ static int ksz9131_get_features(struct > > phy_device *phydev) return 0; > > } > > > > +static int ksz9477_get_features(struct phy_device *phydev) > > +{ > > + __ETHTOOL_DECLARE_LINK_MODE_MASK(zero) = { 0, }; > > + int ret; > > + > > + ret = genphy_read_abilities(phydev); > > + if (ret) > > + return ret; > > + > > + /* KSZ9477 Errata DS80000754C > > + * > > + * Module 4: Energy Efficient Ethernet (EEE) feature > > select must be > > + * manually disabled > > + * The EEE feature is enabled by default, but it is not > > fully > > + * operational. It must be manually disabled through > > register > > + * controls. If not disabled, the PHY ports can > > auto-negotiate > > + * to enable EEE, and this feature can cause link drops > > when linked > > + * to another device supporting EEE. > > + * > > + * Although, the KSZ9477 MMD register > > + * (MMD_DEVICE_ID_EEE_ADV.MMD_EEE_ADV) advertise that > > EEE is > > + * operational one needs to manualy clear them to follow > > the chip > > + * errata. > > + */ > > + linkmode_and(phydev->supported_eee, phydev->supported, > > zero); + > > + return 0; > > +} > > + > > #define KSZ8873MLL_GLOBAL_CONTROL_4 0x06 > > #define KSZ8873MLL_GLOBAL_CONTROL_4_DUPLEX BIT(6) > > #define KSZ8873MLL_GLOBAL_CONTROL_4_SPEED BIT(4) > > @@ -4871,7 +4900,7 @@ static struct phy_driver ksphy_driver[] = { > > .handle_interrupt = kszphy_handle_interrupt, > > .suspend = genphy_suspend, > > .resume = genphy_resume, > > - .get_features = ksz9131_get_features, > > + .get_features = ksz9477_get_features, > > Sorry, i didn't described all details how to implement it. > > This code will break EEE support for the KSZ8563R switch. >
And then another switch (KSZ8563R) pops up.... with regression....
In the micrel.c the ksz9477_get_features was only present in: https://elixir.bootlin.com/linux/latest/source/drivers/net/phy/micrel.c#L4832 https://elixir.bootlin.com/linux/latest/source/drivers/net/phy/micrel.c#L4874 so I only changed it there.
Apparently the KSZ8563R re-uses the KSZ9477 code.
> Please search for MICREL_KSZ8_P1_ERRATA in the kernel source. > Then add new flag, for example MICREL_NO_EEE and use it in a similar > way how MICREL_KSZ8_P1_ERRATA was set and used. With this > implementation, first patch is not needed. > > The code will be something like this: > if (dev_flags & MICREL_NO_EEE) > /* lots of comments */ > linkmode_and(phydev->supported_eee, phydev->supported, zero); > else > /* lots of other comments */ > linkmode_and(phydev->supported_eee, phydev->supported, > PHY_EEE_CAP1_FEATURES); > > On the switch driver side i would expect something like this: > ksz_get_phy_flags(struct dsa_switch *ds, int port) > > swtich (dev->chip_id) > case KSZ8830_CHIP_ID: > .... > break; > case KSZ9477_CHIP_ID: > return MICREL_NO_EEE; >
Ok.
> > Regards, > Oleksij
Best regards,
Lukasz Majewski
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